Lasers containing a photonic crystal layer can radiate laser light toward above the active layer.
A surface emitting quantum cascade laser can be manufactured by forming an active layer, a photonic crystal layer, an upper cladding layer, a contact layer, upper electrodes, and the like in that order on a semiconductor substrate. In this case, the photonic crystal layer includes a region that constitutes grating points of a two-dimensional diffraction grating and, surrounding it, a region having a different refractive index.
With a process for manufacturing a surface emitting laser in which holes are provided in the semiconductor layer using a microcutting process to form grating points and then an upper cladding layer, a contact layer, and the like are grown with the holes remaining, the process is complicated and increasing yield is difficult.